Project Summary/Abstract: Implantable biomedical devices can play an instrumental role in overcoming many of the debilitating diseases, such as Parkinsons, epilepsy, deafness, blindness, brain and nervous system injuries, cardiovascular diseases, incontinence, and others. Many of these diseases are either brought about by injury to the central or peripheral nervous system, or are directly controlled or affected by the electrical signal transmission or operation of the nervous system. Heart pacemakers have been successfully used for decades and have provided a practical and reliable means to many patients with heart problems. Other similar systems are believed to be able to provide similar effect for other diseases. One of the key challenges in the widespread deployment of implantable biomedical devices for these other areas is electrical power. While pacemakers can operate for many years using implantable batteries, they can only do so with limited lifetime, and only with systems that are implanted right under the skin and connected to the needed areas using wires. The other diseases mentioned above need either smaller dimensions, or have to operate deeper inside the body, thus limiting the usefulness of batteries. Wireless power transfer techniques, using electromagnetic, infra-red, or acoustic approaches have been explored, and some have been successfully demonstrated. However, these techniques are still incapable of addressing one of the most important challenges named above, namely limited range. They can provide power to implants to within a range of at best a few centimeters. Future systems have to have a power transfer technique that is more reliable, long-range, and efficient than those in use today. The proposed research aims at developing a highly efficient, long-range and reliable power transfer technique based on electromagnetic transmission between two resonant antennas, one on the inside and the other on the outside of the body. We propose to utilize the near field electromagnetic fields that form around slot-line antennas to couple energy between these two coils. By using proper designs, and using circuit techniques, we have simulated that a power transfer range of as high as 10-20cm can be achieved, with high efficiency, and low power. In addition, this approach is more resilient and less sensitive to misalignment between the two resonant antennas. Furthermore, we propose using arrays of antennas and resonators to further increase transmitted power levels and enhance performance. If successful, this new approach will enable many more of these implants to be operated without batteries, at deeper locations inside the body, thus extending the range and usefulness of implantable systems. In addition, the proposed approach could also increase the received power and efficiency even at shorter ranges than 20cm. If widely used, these implantable devices could provide a significant new tool in monitoring and curing many of these diseases.